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Chapter 6 Antennas

Chapter 6: Antennas

Antennas are the key to radio — without them, signals are not transmitted or received.  Amateurs enjoy building and experimenting with antennas and you will, too!  Section 6 covers this important section in detail.

Table 6-1 Feedline Characteristics

The table printed in the 1st printing of the General Class License Manual is in error. The following table contains the correct typical loss data for several popular types of coaxial cable.  Cable loss and other parameters such as velocity of propagation vary between manufacturers and sometimes from batch to batch.  If you are using the cable in a way that depends on an exact value, measure the cable with test equipment.  The values in the table below were calculated using the on-line calculator at Times-Microwave ().

Type Impedance
Loss per 100 feet (in dB)
at 30 MHz
Loss per 100 feet (in dB)
at 150 MHz
RG8 50 1.08 2.53
RG8X 50 1.96 4.53
RG58 50 2.47 5.63
RG59 75 1.79 4.11
RG174 50 4.56 10.3
RG213 50 1.08 2.53
9913 50 0.68 1.58